title: Boron neutron capture therapy for recurrent high-grade meningiomas.
abstract: OBJECTIVE
  Similar to glioblastomas, high-grade meningiomas are difficult pathologies to control. In this study, the authors used boron neutron capture therapy (BNCT), a tumor-selective intensive particle radiation modality, to treat high-grade meningioma.
  
  
  METHODS
  From June 2005 to September 2011, BNCT was applied 28 times in 20 cases of recurrent high-grade meningioma. All patients had previously undergone intensive treatments such as repetitive surgeries and multiple sessions of radiation therapy. Fluorine-18-labeled boronophenylalanine ((18)F-BPA) PET was performed before BNCT in 19 of the 20 cases; BPA is itself a therapeutic compound. Compound uptake, tumor shrinkage, long-term control rate including survival time, and failure pattern of the treated patients were all evaluated.
  
  
  RESULTS
  Eighteen of 19 cases studied using (18)F-BPA PET showed good BPA uptake, with ratios of tumor to normal brain greater than 2.7. These ratios indicated the likely effects of BNCT prior to neutron irradiation. The original tumor sizes were between 4.3 cm(3) and 109 cm(3). A mean tumor volume reduction of 64.5% was obtained after BNCT within just 2 months. The median follow-up duration was 13 months. Six patients are still alive; at present, the median survival times after BNCT and diagnosis are 14.1 months (95% CI 8.6-40.4 months) and 45.7 months (95% CI 32.4-70.7 months), respectively. Clinical symptoms before BNCT, such as hemiparesis and facial pain, were improved after BNCT in symptomatic cases. Systemic metastasis, intracranial distant recurrence outside the radiation field, CSF dissemination, and local tumor progression were observed in 6, 7, 3, and 3 cases, respectively, during the clinical course. Apparent pseudoprogression was observed in at least 3 cases. Symptomatic radiation injuries occurred in 6 cases, and were controllable in all but 1 case.
  
  
  CONCLUSIONS
  Boron neutron capture therapy may be especially effective in cases of high-grade meningioma.
authors.affiliation: Department of Neurosurgery, Osaka Medical College, Takatsuki;
authors.forename: Shinji
authors.initials: S
authors.lastname: Kawabata
authors.forename: Ryo
authors.initials: R
authors.lastname: Hiramatsu
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Kuroiwa
authors.forename: Koji
authors.initials: K
authors.lastname: Ono
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Miyatake
mesh_terms: D000328:Adult; D000368:Aged; D016754:Boron Neutron Capture Therapy; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008577:Meningeal Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D008579:Meningioma / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D008875:Middle Aged; D060787:Neoplasm Grading; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D016019:Survival Analysis; D015996:Survival Rate; D017211:Treatment Failure; D016896:Treatment Outcome